Trillions of microbes living deep within our planet, at the terrestrial subsurface of more than 2 km, were a mystery …
Angel in the Dark – The Cave-Making Microbe: Thiomonas thermosulfata
Much like the Horta, in “Devil in the Dark”, Star Trek, TOS, this microbe creates lovely crystalline droplets, rather like an Angel’s breath, leaving a silver sheen on cave walls as it carves new ones.